Problem: Luis decided to paint some of the rooms at his 20-room inn, Luis's Place. He discovered he needed $\frac{2}{5}$ of a can of paint per room. If Luis had 2 cans of paint, how many rooms could he paint?
We can divide the cans of paint (2) by the paint needed per room ( $\frac{2}{5}$ of a can) to find out how many rooms Luis could paint. $ \dfrac{{2 \text{ cans of paint}}} {{\dfrac{2}{5} \text{ can per room}}} = {\text{ rooms}} $ Dividing by a fraction is the same as multiplying by the reciprocal. The reciprocal of ${\dfrac{2}{5} \text{ can per room}}$ is ${\dfrac{5}{2} \text{ rooms per can}}$ $ {2\text{ cans of paint}} \times {\dfrac{5}{2} \text{ rooms per can}} = {\text{ rooms}} $ ${\dfrac{10}{2}\text{ rooms}} = 5\text{ rooms}$ Luis could paint 5 rooms.